Lacquer enamel



- the coating; particularly 'addition to the coats normally conducting coating of big 'ing effect when applied protecting UNITED STATES PATENT OFFICE.

WILLIAM F. DOEBFLINGER, 0F ARROCHAR, NEW YORK.

. raocuna ENAMEL.

Ho Drawing.

To all whom it may concern: r 1

Be it known that 1, WILLIAM F. DonnrLINGEma citizen of the United States, Tesiding at Arrochar, in the county of Rich mondand State of New York, have invented certain new and useful Improvements in Lacquer Enamels, of which the following is a specification.

This invention relates to lacquer enamels containing a 'film forming substance, such as a cellulose ester dissolved in a volatile solvent. The'object is to produce a lacquer enamel which will form an electrically nonh strength and durability and high opacity particularly to actinic light in proportion to the weight of for. use as a protective coloring airplane dope to be used for the outer coat or coats in doping airplane wings and fabric.

It is desirable that a rotective coloring airplane lacquer should ry quickly, economizing on time both whenv the lacquer is used in the factoryor in field repairs. It

is desirable that it exert a proper stretcha to airplane fabric on'the frame. This permits substituting a coat or coats ofzprotective coloring enamel lacquer and does applied.

It is necessary that a protective coloring lacquer exert a high protective power in the under coats of lacquer from the disintegrating effect of actinic and that it be itself of high durability ununderlying coats der these conditions. It should be easy to apply pro ducing a smooth even surface, so as not to increase the skin friction of the plane, and the dry coating should be a non conductor of electricity so as not to interfere with the use of wireless, etc.,'on the plane. It. should produce a coating comparatively low. in weight so as not to inthe coating be of a na- Specification of Letters Patent.

incorporating in a suitable'lacquer, a cellulose acetate airplane lacquer, a sultlacquer or wing light and the normal conditions of exposure in use,

by tumbling one c rease the weight of the plane unduly, and it is desirable that ture to permit of ready removal and patch- Patented Jul 6,1920.

Application filed February 6,1919. Serial No. 275,528.

I- produce a protective coloring enamel lacquer having these desirable qualities by such as able ambunt of stannic oxid. I find that about seven (7) ounces of stannic oxid per gallon of lacquer gives good results. As it is desirable that the outer coating of an air plane surface be highly fire resisting, I prefer to use as a base vehicle a lacquer of wh1ch the film forming substance is cellulose acetate.

use the ordinary commercial stannic oxid-the tin oxid of the ceramic industry.

'This is chemically inert, stable, a non-conductor of electricity and is extremely smooth, even and finely divided and can be incorporated without grinding or grinding medium. The fact that it can be used without an oily grinding medium is particularly important in its use with cellulose acetate solutions, which are incompatible with oils. 1' find, that used as I have described, it possesses a remarkable light excluding power in proportion to its weight and bulk. It can be readily tinted to desired shades by incorporating along with it tintingagents, f

such as suitable soluble dyes or pigments wh1ch may be used in very small amount if care is taken to select agents of high tinctorial ,power.

As an example I produce a battleship gray protective coloring airplane lacquer enamel or wing dope, as follows:

A I mix twenty pounds of tin oxid with two gallons of acetone, two gallons of diacetone alcohol, one and one half gallons of benzol and four and one fourth ounces of spirit soluble jet nigrosin previously dissolved in one and one half uarts of diacetone alcohol alf hour or so in a tumbling barrel. I then add the solution of twenty-four pounds of cellulose acetate in twenty-four and one half gallons acetone, five gallons diacetone alcohol and twelve and one half gallons of benzol and mix thoroughly by tumbling several hours. -This produces a lacqper which works well in application, and in which the tin oxid has little tendency to settle. Although containing only about seven ounces of pigment per gallon,'it is remarkably efficient in protecting underlying cellulose acetate or cellulose nitrate lacquer and produces a coating which is itself very strong and durable. It dries with the normal stretching effect of a cellulose acetate wing dope and the coating ma be used.

is smooth and of attractlve appearance. The presence of high boiling cellulose acetate solvent in cellulose acetate enamels greatly improves the working; qualities of the enamel and the wearing qualities of the film resulting in use. In general I prefer to use I diacetone alcohol'as the high boiling solvent as in the illustrative example but other suitable high boiling cellulose acetate solvent produce difl'erent colors other dyes or pigments may be used in small amountin .place of the nigrosin.

r, its frame) In coatin airplane fabric (stretched on coats of ordinary wing dope, which may be an acetate dope of substantially similar composition to my enamel,'without the tin oxid and nigrosin and preferably with a somewhat smaller proportion of diacetone alcohol and benzol, and then one or two coats 7 of my battleship gray enamel, allowing each 5 coat to. dry before applying the next.

The composition can, of varied without departing v prising a'cellulose ester dissolved in a vola-.

- F or ordinary lacquer, particularly for use on rigid surfaces such as metal or wood, I

L'A cellulose ester enamel lacquer comprefer to give the fabric three tile liquid to form a free flowing solution,

and suspended stannic oxid; ester, solvent and stannic oxid being in such proportions, and solvent of such volatility as to form an enamel lacquer which-can be readily applied to a supporting surface with abrush, and which when so applied will dry quicklyproducing a smooth even surface; substantially as described.

2. An enamal lacquer comprising cellulose acetate dissolved in a volatile solvent and suspended stannic oxid.

3. A protective coloring airplane lacquer comprising dissolved cellulose acetate, very volatile liquid in major amount, high boiling cellulose acetate solvent in minor amount, and inert light excluding agent of which stannic oxid is a constituent.

4. A protective coloring airplane lacquer comprising dissolved cellulose acetate, acetone, diacetone alcohol and stannic oxid, substantially as described.

5. A protective coloring airplane lacquer comprising dissolved cellulose acetate, acetone, diacetone alcohol, stannic oxid and dissolved nigrosin substantially as described.

6. An enamel lacquer containing-sufiicient suspended stannic oxid to render the dry film formed on evaporation of a la er of the lacquer enamel opaque to'actinic light.-

7. An airplane lacquer containing suspended stannic oxid.

WILLIAM F. DOERFLIN GER. Witnesses:

PERRY O. P. VAN ISUZER. 

